Include <limits.h>.

Include <limits.h>.
(dev_from_mount_options)
[defined MOUNTED_GETMNTENT1 || defined MOUNTED_GETMNTENT2]:
New function.  It no longer assumes "dev=" has the System V meaning
on Linux (since it doesn't).  It also parses "dev=" more carefully.
(read_file_system_list)
[defined MOUNTED_GETMNTENT1 || defined MOUNTED_GETMNTENT2]: Use it.
MOUNTED_GETMNTENT2 is new here; the code didn't used to look for
dev= in that case.