Fixed four ufs-related coverity issues.
The coverity issues and fixes are as follows
1. CID 1519042: Security issue with the rand() function
Changed to use a fixed value (0xab) instead of rand() as
the value for testing
2. CID 1519043: Dereference after null check
Removed useless (redundant) null checks
3. CID 1519050: Out-of-bounds access issue
Fix to pass an array type variable to find_first_bit and
find_next_bit using DECLARE_BITMAP()
4. CID 1519051: Out-of-bounds read issue
Fix incorrect range check for lun
Fix coverity CID: 1519042 1519043 1519050 1519051
Signed-off-by: Jeuk Kim <jeuk20.kim@samsung.com>
97970dae53