patman: Minor help message/README fixes

A few of the help messages are not quite right, and there is a typo
in the README. Fix these.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Doug Anderson <dianders@chromium.org>
diff --git a/tools/patman/patman.py b/tools/patman/patman.py
index 377408d..5000b7d 100755
--- a/tools/patman/patman.py
+++ b/tools/patman/patman.py
@@ -49,7 +49,7 @@
        dest='ignore_errors', default=False,
        help='Send patches email even if patch errors are found')
 parser.add_option('-n', '--dry-run', action='store_true', dest='dry_run',
-       default=False, help="Do a try run (create but don't email patches)")
+       default=False, help="Do a dry run (create but don't email patches)")
 parser.add_option('-p', '--project', default=project.DetectProject(),
                   help="Project name; affects default option values and "
                   "aliases [default: %default]")
@@ -72,7 +72,7 @@
 parser.usage = """patman [options]
 
 Create patches from commits in a branch, check them and email them as
-specified by tags you place in the commits. Use -n to """
+specified by tags you place in the commits. Use -n to do a dry run first."""
 
 
 # Parse options twice: first to get the project and second to handle