Remove part of comment for b-g#11122 that is no longer true.

# value is written to a makefile, which interprets away one level of

# dollar-signs.  So, interpretation stages are  m4 and then shell in autoconf,

# then Make, then shell.

#

# We use  grep -E Foo space-or-EOL  so that we don't falsely match "Foo_safe" .

# Assumption is that if there are parameters, the system represents them using 

# space as a seperator.  This has the side effect that the matching expression 

# does not match itself, and so grep won't self-match.

AC_PATH_PROG(PS, ps, ps)

AC_MSG_CHECKING("how to check if pid exists")

PS=$ac_cv_path_PS