Update exit code information in the hbal man page

Also fixes a small typo.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Adeodato Simo <dato@google.com>

man/hbal.rst

@@ -460,8 +460,9 @@ The options that can be passed to the program are as follows:
 EXIT STATUS
 -----------
 
-The exist status of the command will be zero, unless for some reason
-the algorithm fatally failed (e.g. wrong node or instance data).
+The exit status of the command will be zero, unless for some reason
+the algorithm fatally failed (e.g. wrong node or instance data), or
+(in case of job execution) any job has failed.
 
 ENVIRONMENT
 -----------