fixed unassigned value to a intent(out) variable

Author: degawa

src/stdlib_io_npy_load.fypp

@@ -185,6 +185,9 @@ contains
 
         integer :: minor
 
+        ! stat should be zero if no error occurred
+        stat = 0
+
         if (header(1:1) /= magic_number) then
             stat = 1
             msg = "Expected z'93' but got z'"//to_string(ichar(header(1:1)))//"' "//&