security/snoopy: Fix build on 14-CURRENT

tid.c:52:23: error: incompatible pointer to integer conversion initializing 'unsigned long' with an expression of type 'pthread_t' (aka 'struct pthread *') [-Wint-conversion]
    long unsigned int tid = pthread_self();
                      ^     ~~~~~~~~~~~~~~
1 error generated.

Reference:	https://pkg-status.freebsd.org/beefy18/data/main-amd64-default/p100a5c5dca85_sb347c22846/logs/snoopy-2.4.15.log

security/snoopy/files/patch-src-datasource-tid.c

@@ -0,0 +1,11 @@
+--- src/datasource/tid.c.orig	2021-04-20 15:35:54 UTC
++++ src/datasource/tid.c
+@@ -49,7 +49,7 @@
+  */
+ int snoopy_datasource_tid (char * const result, char const * const arg)
+ {
+-    long unsigned int tid = pthread_self();
++    long unsigned int tid = (long unsigned int) pthread_self();
+
+     // This happens if -lpthread is not given to compiler
+     if (0 == tid) {