MAINTAINERS: remove duplicate bug filling description

I have noticed that two different descriptions for B: entries in
MAINTAINERS were merged: commit 68656443 ("MAINTAINERS: Add bug
tracking system location entry type") and 2de2bd95 ("MAINTAINERS:
add "B:" for URI where to file bugs").

This patch keeps the description from 2de2bd95.  There has been a
discussion [1] about whether this more detailed description is useful
and what it exactly implies.  I find it more useful and general, and the
author of 68656443 agreed in the end that either is fine.

[1] https://lkml.org/lkml/2016/12/8/71

Link: http://lkml.kernel.org/r/20161219085158.12114-1-vbabka@suse.cz


Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>