basic/util: rename u64log2 to log2u64

u64log2 was strangely named. We even have log2i and log2u right below
in that file.

src/basic/capability-util.c

@@ -336,7 +336,7 @@ int drop_privileges(uid_t uid, gid_t gid, uint64_t keep_capabilities) {
 
         /* Now upgrade the permitted caps we still kept to effective caps */
         if (keep_capabilities != 0) {
-                cap_value_t bits[u64log2(keep_capabilities) + 1];
+                cap_value_t bits[log2u64(keep_capabilities) + 1];
                 _cleanup_cap_free_ cap_t d = NULL;
                 unsigned i, j = 0;
 

src/basic/util.h

@@ -22,7 +22,7 @@ void in_initrd_force(bool value);
 
 int on_ac_power(void);
 
-static inline unsigned u64log2(uint64_t n) {
+static inline unsigned log2u64(uint64_t n) {
 #if __SIZEOF_LONG_LONG__ == 8
         return (n > 1) ? (unsigned) __builtin_clzll(n) ^ 63U : 0;
 #else