ktest: Fix some typos in config-bisect.pl

This patch fixes some spelling typos in config-bisect.pl

Link: http://lkml.kernel.org/r/20190723032445.14220-1-standby24x7@gmail.com

Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>