Description of problem:
When somebody runs blkrawverify with non-existent file as argument, it does not complain. Exit code is zero.

Version-Release number of selected component (if applicable):
blktrace-1.0.0-5.el5

How reproducible:
always

Steps to Reproduce:
# blktrace -w 5 -d /dev/hdb
Device: /dev/hdb
  CPU  0:                    0 events,        0 KiB data
  CPU  1:                    0 events,        3 KiB data
  CPU  2:                    0 events,        0 KiB data
  CPU  3:                    0 events,        0 KiB data
  CPU  4:                    0 events,        0 KiB data
  CPU  5:                    0 events,        0 KiB data
  CPU  6:                    0 events,        0 KiB data
  CPU  7:                    0 events,        0 KiB data
  Total:                     0 events (dropped 0),        3 KiB data
# ls -l hdb*
-rw-r--r-- 1 root root    0 May  7 06:05 hdb.blktrace.0
-rw-r--r-- 1 root root 2592 May  7 06:05 hdb.blktrace.1
-rw-r--r-- 1 root root    0 May  7 06:05 hdb.blktrace.2
-rw-r--r-- 1 root root    0 May  7 06:05 hdb.blktrace.3
-rw-r--r-- 1 root root    0 May  7 06:05 hdb.blktrace.4
-rw-r--r-- 1 root root    0 May  7 06:05 hdb.blktrace.5
-rw-r--r-- 1 root root    0 May  7 06:05 hdb.blktrace.6
-rw-r--r-- 1 root root    0 May  7 06:05 hdb.blktrace.7
# rm -f hdb*
# blkrawverify hdb
Verifying hdb
# echo $?
0
  
Actual results:
no error message appears
exit code == 0

Expected results:
an error message appears (e.g. "no hdb* files found")
exit code != 0