libquota: remove get_qf_name()

libquota: remove get_qf_name()

The get_qf_name() function used PATH_MAX, which is non-portable.
Worse, it blindly assumed that PATH_MAX was the size of the buffer
passed to it --- which in the one and only place where it was used in
libquota, was a buffer declared to a fixed size 256 bytes.

Fix this by simply getting rid of the function altogether.

Cc: Aditya Kali <adityakali@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>