mkfs.cramfs: clean up gcc warnings

mkfs.cramfs: clean up gcc warnings

* clean up code, gcc warnings
  (try compilation with "-Wall -Wp,-D_FORTIFY_SOURCE=2")

Builds cleanly on x86_32 and x86_64.

mkfs.cramfs.c:211: warning: pointer targets in passing argument 2 of 'MD5Update' differ in signedness
mkfs.cramfs.c:336: warning: format '%u' expects type 'unsigned int', but argument 4 has type 'size_t'
mkfs.cramfs.c:355: warning: pointer targets in assignment differ in signedness
mkfs.cramfs.c:448: warning: pointer targets in passing argument 1 of '__builtin___strncpy_chk' differ in signedness
mkfs.cramfs.c:448: warning: pointer targets in passing argument 1 of '__strncpy_ichk' differ in signedness
mkfs.cramfs.c:450: warning: pointer targets in passing argument 1 of '__builtin___strncpy_chk' differ in signedness
mkfs.cramfs.c:450: warning: pointer targets in passing argument 1 of '__strncpy_ichk' differ in signedness
mkfs.cramfs.c:490: warning: pointer targets in passing argument 1 of 'strlen' differ in signedness
mkfs.cramfs.c:620: warning: pointer targets in passing argument 1 of 'compress' differ in signedness
mkfs.cramfs.c:620: warning: pointer targets in passing argument 3 of 'compress' differ in signedness
mkfs.cramfs.c:671: warning: pointer targets in passing argument 3 of 'do_compress' differ in signedness
mkfs.cramfs.c:824: warning: format '%Ld' expects type 'long long int', but argument 4 has type 'loff_t'
mkfs.cramfs.c:872: warning: format '%d' expects type 'int', but argument 3 has type 'ssize_t'
mkfs.cramfs.c:880: warning: format '%d' expects type 'int', but argument 3 has type 'ssize_t'
mkfs.cramfs.c:885: warning: format '%d' expects type 'int', but argument 3 has type 'long unsigned int'
mkfs.cramfs.c:889: warning: pointer targets in passing argument 2 of 'crc32' differ in signedness
mkfs.cramfs.c:896: warning: format '%Ld' expects type 'long long int', but argument 4 has type 'loff_t'
mkfs.cramfs.c:896: warning: format '%d' expects type 'int', but argument 5 has type 'ssize_t'
mkfs.cramfs.c:909: warning: format '%d' expects type 'int', but argument 4 has type 'ssize_t'
mkfs.cramfs.c:909: warning: format '%d' expects type 'int', but argument 5 has type 'ssize_t'

Co-Author: Karel Zak <kzak@redhat.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Karel Zak <kzak@redhat.com>