trylink: use "mktemp tmp.XXXXXXXXXX" to placate OS X

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

scripts/trylink

@@ -46,7 +46,7 @@ try() {
 }
 
 check_cc() {
-    local tempname="$(mktemp)"
+    local tempname="$(mktemp tmp.XXXXXXXXXX)"
     local r
     echo "int main(int argc,char**argv){return argv?argc:0;}" >"$tempname".c
     # Can use "-o /dev/null", but older gcc tend to *unlink it* on failure! :(
@@ -61,7 +61,7 @@ check_cc() {
 }
 
 check_libc_is_glibc() {
-    local tempname="$(mktemp)"
+    local tempname="$(mktemp tmp.XXXXXXXXXX)"
     local r
     echo "\
 	#include <stdlib.h>