xfrm: use "unsigned int" in addr_match()

x86_64 is zero-extending arch so "unsigned int" is preferred over "int"
for address calculations and extending to size_t.

Space savings:

	add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-24 (-24)
	function                                     old     new   delta
	xfrm_state_walk                              708     696     -12
	xfrm_selector_match                          918     906     -12
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

include/net/xfrm.h

@@ -816,12 +816,12 @@ static inline void xfrm_state_hold(struct xfrm_state *x)
 }
 
 static inline bool addr_match(const void *token1, const void *token2,
-			      int prefixlen)
+			      unsigned int prefixlen)
 {
 	const __be32 *a1 = token1;
 	const __be32 *a2 = token2;
-	int pdw;
-	int pbi;
+	unsigned int pdw;
+	unsigned int pbi;
 
 	pdw = prefixlen >> 5;	  /* num of whole u32 in prefix */
 	pbi = prefixlen &  0x1f;  /* num of bits in incomplete u32 in prefix */