busybox: fix non-portable invocation of mktemp

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 47289

package/utils/busybox/patches/102-trylink_mktemp_fix.patch

+--- a/scripts/trylink
++++ b/scripts/trylink
+@@ -46,7 +46,7 @@ try() {
+ }
+ 
+ check_cc() {
+-    local tempname="$(mktemp)"
++    local tempname="$(mktemp /tmp/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/tmp.XXXXXXXXXX)"
+     local r
+     echo "\
+ 	#include <stdlib.h>