Fixed size_t comparison in memxxx and strxxx finctions.

src/libc/compat/memccpy.c

@@ -18,7 +18,7 @@ memccpy(vt, vf, c, n)
 	register char *t = vt;
 	register const char *f = vf;
 
-	while (--n >= 0)
+	while (n-- > 0)
 		if ((*t++ = *f++) == c)
 			return (t);
 	return (0);

src/libc/compat/memchr.c

@@ -16,7 +16,7 @@ memchr(vs, c, n)
 {
 	register const char *s = vs;
 
-	while (--n >= 0)
+	while (n-- > 0)
 		if (*s++ == c)
 			return (void*) --s;
 	return (0);

src/libc/compat/memcmp.c

@@ -15,7 +15,7 @@ memcmp (vs1, vs2, n)
 {
 	register const char *s1 = vs1, *s2 = vs2;
 
-	while (--n >= 0)
+	while (n-- > 0)
 		if (*s1++ != *s2++)
 			return (*--s1 - *--s2);
 	return (0);

src/libc/compat/memcpy.c

@@ -17,7 +17,7 @@ memcpy (vt, vf, n)
 	register char *t = vt;
 	register const char *f = vf;
 
-	while (--n >= 0)
+	while (n-- > 0)
 		*t++ = *f++;
 
 	return vt;

src/libc/compat/memset.c

@@ -16,7 +16,7 @@ memset (vs, c, n)
 {
 	register char *s = vs;
 
-	while (--n >= 0)
+	while (n-- > 0)
 		*s++ = c;
 
 	return vs;

src/libc/gen/strcasecmp.c

@@ -64,8 +64,8 @@ strncasecmp(s1, s2, n)
 {
 	register char *cm = charmap;
 
-	while (--n >= 0 && cm[(unsigned char)*s1] == cm[(unsigned char)*s2++])
+	while (n-- > 0 && cm[(unsigned char)*s1] == cm[(unsigned char)*s2++])
 		if (*s1++ == '\0')
 			return(0);
-	return(n < 0 ? 0 : cm[(unsigned char)*s1] - cm[(unsigned char)*--s2]);
+	return(n == 0 ? 0 : cm[(unsigned char)*s1] - cm[(unsigned char)*--s2]);
 }

src/libc/gen/strncat.c

@@ -18,7 +18,7 @@ strncat(s1, s2, n)
 		;
 	--s1;
 	while ((*s1++ = *s2++))
-		if (--n < 0) {
+		if (n-- == 0) {
 			*--s1 = '\0';
 			break;
 		}

src/libc/gen/strncpy.c

@@ -10,7 +10,7 @@ strncpy(s1, s2, n)
 	register const char *s2;
 	size_t n;
 {
-	register int i;
+	size_t i;
 	register char *os1;
 
 	os1 = s1;