getLongLongFromObject: use string2ll() instead of strict_strtoll().

strict_strtoll() has a bug that reports the empty string as ok and
parses it as zero.

Apparently nobody ever replaced this old call with the faster/saner
string2ll() which is used otherwise in the rest of the Redis core.

This commit close redis#3333.

src/object.c

@@ -619,20 +619,6 @@ int getLongDoubleFromObjectOrReply(client *c, robj *o, long double *target, cons
     return C_OK;
 }
 
-/* Helper function for getLongLongFromObject(). The function parses the string
- * as a long long value in a strict way (no spaces before/after). On success
- * C_OK is returned, otherwise C_ERR is returned. */
-int strict_strtoll(char *str, long long *vp) {
-    char *eptr;
-    long long value;
-
-    errno = 0;
-    value = strtoll(str, &eptr, 10);
-    if (isspace(str[0]) || eptr[0] != '\0' || errno == ERANGE) return C_ERR;
-    if (vp) *vp = value;
-    return C_OK;
-}
-
 int getLongLongFromObject(robj *o, long long *target) {
     long long value;
 
@@ -641,7 +627,7 @@ int getLongLongFromObject(robj *o, long long *target) {
     } else {
         serverAssertWithInfo(NULL,o,o->type == OBJ_STRING);
         if (sdsEncodedObject(o)) {
-            if (strict_strtoll(o->ptr,&value) == C_ERR) return C_ERR;
+            if (string2ll(o->ptr,sdslen(o->ptr),&value) == 0) return C_ERR;
         } else if (o->encoding == OBJ_ENCODING_INT) {
             value = (long)o->ptr;
         } else {