os_unix: Log exit code before freeing all memory

When building with -DEXITFREE, the ILOG call would result in a crash
trying to access VV_PROGPATH, which had already been released:

    (gdb) bt
    #0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51
    #1  0x00007f8f761082f1 in __GI_abort () at abort.c:79
    #2  0x00007f8f760ffa8a in __assert_fail_base (fmt=0x7f8f76253ec8 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n",
        assertion=assertion@entry=0x1c74280 <.str.8> " ,\t\n", file=file@entry=0x1c73fe2 "256]'", line=line@entry=610,
        function=function@entry=0x1c742e0 <.str.9+32> "") at assert.c:92
    #3  0x00007f8f760ffb02 in __GI___assert_fail (assertion=0x1c74280 <.str.8> " ,\t\n", file=0x1c73fe2 "256]'", line=610,
        function=0x1c742e0 <.str.9+32> "") at assert.c:101
    #4  0x00000000012d87c1 in vim_getenv (name=0x2f5a460 <get_special_key_name.string+64> "NVIM_LOG_FILE") at ../src/nvim/os/env.c:608
    #5  0x00000000012d6538 in expand_env_esc (srcp=0x1c2f4e0 <.str.10+32> "",
        dst=0x2f5a460 <get_special_key_name.string+64> "NVIM_LOG_FILE", dstlen=4095, esc=false, one=false, prefix=0x0)
        at ../src/nvim/os/env.c:351
    #6  0x00000000012d85af in expand_env_esc (srcp=0x625000000100 "\004", dst=0x7ffeed88cf40 "", dstlen=32766, esc=237, one=136,
        prefix=0x60200401c8b4 <error: Cannot access memory at address 0x60200401c8b4>) at ../src/nvim/os/env.c:472
    #7  0x0000000000eb4274 in do_log_to_file (log_file=0x0, log_level=0, context=0x0, func_name=0x0, line_num=0, eol=false, fmt=0x0)
        at ../src/nvim/log.c:254
    #8  0x0000000000eb305b in open_log_file () at ../src/nvim/log.c:164
    #9  0x0000000000eb2cc6 in logmsg (log_level=<error reading variable: Cannot access memory at address 0x268>,
        context=<error reading variable: Cannot access memory at address 0x260>,
        func_name=<error reading variable: Cannot access memory at address 0x258>,
        line_num=<error reading variable: Cannot access memory at address 0x254>,
        eol=<error reading variable: Cannot access memory at address 0x253>,
        fmt=<error reading variable: Cannot access memory at address 0x248>) at ../src/nvim/log.c:109
    #10 0x00000000013022c7 in mch_free_acl (aclent=0x4f59100) at ../src/nvim/os_unix.c:132
    #11 0x0000000000efddac in getout (exitval=0) at ../src/nvim/main.c:681
    #12 0x0000000000c1bb3e in ex_quit (eap=0x7ffeed88cd00) at ../src/nvim/ex_docmd.c:6067
    #13 0x0000000000bab781 in do_one_cmd (cmdlinep=0x7ffeed88f180, flags=10, cstack=0x7ffeed88f1a0, fgetline=0x0, cookie=0x0)
        at ../src/nvim/ex_docmd.c:2228
    #14 0x0000000000b8de6d in do_cmdline (cmdline=0x7ffeed891ae2 "quit", fgetline=0x0, cookie=0x0, flags=10)
        at ../src/nvim/ex_docmd.c:592
    #15 0x0000000000b94036 in do_cmdline_cmd (cmd=0x7ffeed891ae2 "quit") at ../src/nvim/ex_docmd.c:268
    #16 0x0000000000efb900 in exe_commands (parmp=0x7ffeed890900) at ../src/nvim/main.c:1699
    #17 0x0000000000ee96b2 in main (argc=11, argv=0x7ffeed890fa8) at ../src/nvim/main.c:524

1 files changed, 2 insertions, 1 deletions

diff --git a/src/nvim/os_unix.c b/src/nvim/os_unix.c
index 27660712da..09ba718302 100644
--- a/src/nvim/os_unix.c
+++ b/src/nvim/os_unix.c
@@ -149,11 +149,12 @@ void mch_exit(int r)
     stream_set_blocking(input_global_fd(), true);  // normalize stream (#2598)
   }
 
+  ILOG("Nvim exit: %d", r);
+
 #ifdef EXITFREE
   free_all_mem();
 #endif
 
-  ILOG("Nvim exit: %d", r);
   exit(r);
 }