osdc/Striper.cc: fix another OVERFLOW_BEFORE_WIDEN

Fix for:

CID 1247720 (#1 of 1): Unintentional integer overflow
(OVERFLOW_BEFORE_WIDEN)
 overflow_before_widen: Potentially overflowing expression
 stripe_count * stripe_unit with type unsigned int (32 bits,
 unsigned) is evaluated using 32-bit arithmetic before being
 used in a context which expects an expression of type
 uint64_t (64 bits, unsigned).

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>

Author: dalgaaf

src/osdc/Striper.cc

@@ -222,7 +222,7 @@ uint64_t Striper::get_num_objects(const ceph_file_layout& layout, uint64_t size)
   uint64_t num_periods = (size + period - 1) / period;
   uint64_t remainder_bytes = size % period;
   uint64_t remainder_objs = 0;
-  if ((remainder_bytes > 0) && (remainder_bytes < stripe_count * stripe_unit))
+  if ((remainder_bytes > 0) && (remainder_bytes < (uint64_t)stripe_count * stripe_unit))
     remainder_objs = stripe_count - ((remainder_bytes + stripe_unit - 1) / stripe_unit);
   return num_periods * stripe_count - remainder_objs;
 }