fuse2fs: clean up error messages

fuse2fs: clean up error messages

Instead of horridly line-wrapping multi-line messages that are printed
during mounting, let's just expand them to be one source code line per
printed line.  This will make it a lot easier for someone who sees the
these errors to grep the source code to find out where they came from.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/174786677603.1383760.817536477752866097.stgit@frogsfrogsfrogs
Signed-off-by: Theodore Ts'o <tytso@mit.edu>