libquota: quiet log_err() bad format warnings

The macro for log_err() was written so that it needed to always
have an argument, but GCC was unhappy to have an argument when
none was specified in the format string.  Use the CPP "##" to
eat the preceeding comma if no argument is specified.

Signed-off-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
5 files changed