Detect realloc failure
While reviewing other commits, a call to realloc() was discovered that
would leak memory on failure (by virtue of always assigning the realloc()
return value to the pointer holding the input address, even when the
return value is NULL). Check for failure and return early in that case
(giving an incomplete list of events).
Change-Id: Ic6e889f1d990bd289812ce4bf8e9cd4ebce488ec
Reviewed-on: https://gerrit.openafs.org/13313
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>