Add #ifdefs to make POSIX header tests pass for musl

Bug: 265874089
Test: m USE_HOST_MUSL=true libbionic_tests_headers_posix
Change-Id: I6ae3ed3b91d5389f838b4a4f66c86bb00a27561a
diff --git a/tests/headers/posix/fcntl_h.c b/tests/headers/posix/fcntl_h.c
index a55fe89..418add0 100644
--- a/tests/headers/posix/fcntl_h.c
+++ b/tests/headers/posix/fcntl_h.c
@@ -84,7 +84,11 @@
 
   // POSIX: "The <fcntl.h> header shall define the symbolic constants for
   // file modes for use as values of mode_t as described in <sys/stat.h>."
+  // Musl only defines the file mode bits (S_IFUSR, etc.) and not the file
+  // type bits (S_IFMT, etc.).
+#if !defined(ANDROID_HOST_MUSL)
 #include "sys_stat_h_mode_constants.h"
+#endif
 
   MACRO(AT_FDCWD);
 #if !defined(__BIONIC__) // See comment in "faccessat.cpp".