Don't return statically-allocated string as an error message
Don't return statically-allocated string as an error message

It could be better to return statically-allocated data in those cases, but we
don't do it anywhere else. Should be probably fixed generally in some future
patch.

atodorov/libblockdev,rhinstaller/libblockdev,snbueno/libblockdev,dashea/libblockdev,dashea/libblockdev,vpodzime/libblockdev,rhinstaller/libblockdev,vpodzime/libblockdev,snbueno/libblockdev,rhinstaller/libblockdev,vpodzime/libblockdev,atodorov/libblockdev,atodorov/libblockdev