Minor fixes to some spacing.

libs/libc/stdlib/lib_strtoul.c

@@ -134,6 +134,7 @@ unsigned long strtoul(FAR const char *nptr, FAR char **endptr, int base)
               nptr--;
             }
         }
+
       *endptr = (FAR char *)nptr;
     }
 

libs/libc/stdlib/lib_strtoull.c

@@ -136,6 +136,7 @@ unsigned long long strtoull(FAR const char *nptr, FAR char **endptr, int base)
               nptr--;
             }
         }
+
       *endptr = (FAR char *)nptr;
     }