LU-3963 libcfs: Use kernel's strncasecmp and remove cfs_get_blocked_sigs

LU-3963 libcfs: Use kernel's strncasecmp and remove cfs_get_blocked_sigs

Remove libcfs function cfs_strncasecmp() since the kernel
already has its own strncasecmp(). Lastly remove from libcfs.h
cfs_get_blocked_sigs() since this function no longer exist.

Change-Id: Ief5bac8ac23114c8e34d988906b06dda8eb77306
Signed-off-by: James Simmons <uja.ornl@gmail.com>
Reviewed-on: http://review.whamcloud.com/13070
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Tested-by: Jenkins
Reviewed-by: Patrick Farrell <paf@cray.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>