Cygwin: mmap_list::try_map: fix a condition in a test of an mmap request

In testing whether the requested area is contained in an existing
mapped region, an incorrect condition was used due to a
misinterpretation of the u_addr and u_len variables.

Addresses: https://cygwin.com/pipermail/cygwin/2024-December/256913.html
Fixes: c68de3a ("* mmap.cc (class mmap_record):
Declare new map_pages method with address parameter.")
Signed-off-by: Ken Brown <[email protected]>

Author: kbrow1i

winsup/cygwin/mm/mmap.cc

@@ -651,7 +651,7 @@ mmap_list::try_map (void *addr, size_t len, int new_prot, int flags, off_t off)
 	  break;
       if (rec)
 	{
-	  if (u_addr > (caddr_t) addr || u_addr + len < (caddr_t) addr + len
+	  if (u_addr > (caddr_t) addr || u_addr + u_len < (caddr_t) addr + len
 	      || !rec->compatible_flags (flags))
 	    {
 	      /* Partial match only, or access mode doesn't match. */