[glibc] mach: Fix incoherency between perror and strerror

[Samuel Thibault <sthibaul@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=03ad444e8e086391f53d87c3949e0d44adef4bc3

commit 03ad444e8e086391f53d87c3949e0d44adef4bc3
Author: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date:   Sat Aug 27 13:52:46 2022 +0200

    mach: Fix incoherency between perror and strerror
    
    08d2024b4167 ("string: Simplify strerror_r") inadvertently made
    __strerror_r print unknown error system in decimal while the original
    code was printing it in hexadecimal. perror was kept printing in
    hexadecimal in 725eeb4af14c ("string: Use tls-internal on strerror_l"),
    let us keep both coherent.
    
    This also fixes a duplicate ':'
    
    Spotted by the libunistring testsuite test-perror2

Diff:
---
 sysdeps/mach/_strerror.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sysdeps/mach/_strerror.c b/sysdeps/mach/_strerror.c
index b179c440d3..acc00612bb 100644
--- a/sysdeps/mach/_strerror.c
+++ b/sysdeps/mach/_strerror.c
@@ -40,7 +40,7 @@ __strerror_r (int errnum, char *buf, size_t buflen)
 
   if (system > err_max_system || ! __mach_error_systems[system].bad_sub)
     {
-      __snprintf (buf, buflen, "%s: %d", _("Error in unknown error system: "),
+      __snprintf (buf, buflen, "%s%X", _("Error in unknown error system: "),
 		  errnum);
       return buf;
     }