libselinux: Do not define gettid() if glibc >= 2.30 is used

Since version 2.30 glibc implements gettid() system call wrapper, see
https://sourceware.org/bugzilla/show_bug.cgi?id=6399

Fixes:
cc -O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -fexceptions -fstack-protector-strong -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -I../include -D_GNU_SOURCE  -DNO_ANDROID_BACKEND   -c -o procattr.o procattr.c
procattr.c:28:14: error: static declaration of ‘gettid’ follows non-static declaration
   28 | static pid_t gettid(void)
      |              ^~~~~~
In file included from /usr/include/unistd.h:1170,
                 from procattr.c:2:
/usr/include/bits/unistd_ext.h:34:16: note: previous declaration of ‘gettid’ was here
   34 | extern __pid_t gettid (void) __THROW;
      |                ^~~~~~

Signed-off-by: Petr Lautrbach <plautrba@redhat.com>
1 file changed