bsd-user: Use page_check_range_empty for MAP_EXCL

The previous check returned -1 when any page within
[start, start+len) is unmapped, not when all are unmapped.

Cc: Warner Losh <imp@bsdimp.com>
Cc: Kyle Evans <kevans@freebsd.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Message-Id: <20230707204054.8792-11-richard.henderson@linaro.org>

bsd-user/mmap.c

@@ -609,7 +609,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
         }
 
         /* Reject the mapping if any page within the range is mapped */
-        if ((flags & MAP_EXCL) && page_check_range(start, len, 0) < 0) {
+        if ((flags & MAP_EXCL) && !page_check_range_empty(start, end - 1)) {
             errno = EINVAL;
             goto fail;
         }