x86/alternative: Drop not needed test after call of alt_replace_call()

alt_replace_call() will never return a negative value, so testing the
return value to be less than zero can be dropped.

This makes it possible to switch the return type of alt_replace_call()
and the type of insn_buff_sz to unsigned int.

Signed-off-by: Juergen Gross <[e-mail]>
Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>

arch/x86/kernel/alternative.c

···
  * Rewrite the "call BUG_func" replacement to point to the target of the
  * indirect pv_ops call "call *disp(%ip)".
  */
-static int alt_replace_call(u8 *instr, u8 *insn_buff, struct alt_instr *a)
+static unsigned int alt_replace_call(u8 *instr, u8 *insn_buff, struct alt_instr *a)
 {
 	void *target, *bug = &BUG_func;
 	s32 disp;
···
 	 * order.
 	 */
 	for (a = start; a < end; a++) {
-		int insn_buff_sz = 0;
+		unsigned int insn_buff_sz = 0;
 
 		/*
 		 * In case of nested ALTERNATIVE()s the outer alternative might
···
 		memcpy(insn_buff, replacement, a->replacementlen);
 		insn_buff_sz = a->replacementlen;
 
-		if (a->flags & ALT_FLAG_DIRECT_CALL) {
+		if (a->flags & ALT_FLAG_DIRECT_CALL)
 			insn_buff_sz = alt_replace_call(instr, insn_buff, a);
-			if (insn_buff_sz < 0)
-				continue;
-		}
 
 		for (; insn_buff_sz < a->instrlen; insn_buff_sz++)
 			insn_buff[insn_buff_sz] = 0x90;