Update x86_ops_bcd.h

Reverted the AAM instruction to again set the divisor to 10 when 0 is specified.

src/cpu/x86_ops_bcd.h

@@ -31,14 +31,7 @@ static int opAAD(uint32_t fetchdat)
 static int opAAM(uint32_t fetchdat)
 {
         int base = getbytef();
-
-        if (base == 0) {
-		x86de(NULL, 0);
-		return 1;
-	}
-
-        if (!cpu_isintel) base = 10;
-
+        if (!base || !cpu_isintel) base = 10;
         AH = AL / base;
         AL %= base;
         setznp16(AX);