slabtop check has optional spaces at start of line

slabtop check has optional spaces at start of line

There is a race condition between expect script consuming the output
from slabtop. There were a sequences of lines that looked like
^\d+ ... \s*
with the last \s* consuming the first space on the start of the line.
However if the line takes too long to print, then expect stops there and
the space at the start of the subsquent line does not match.

The solution is a \s* at the start ofthe line.