patch: avoid whitespace in patches_sha1
patch: avoid whitespace in patches_sha1

Prior to this change, the debian/rules file would introduce a newline
each time I ran "rhcephpkg patch". (Since we were't quoting the value in
debian/rules, this ended up being harmless by coincidence.)

Trim the output of the sha1 discovery command so that the patches_sha1
string no longer contains a trailing newline.

red-hat-storage/rhcephpkg,red-hat-storage/rhcephpkg