docs: write arguments as upper case in manpages

refs #3780, #3864

Change-Id: Iff0534dbd0119734fdb567500fe2e1842c7805f5
diff --git a/docs/manpages/nfdc-status.rst b/docs/manpages/nfdc-status.rst
index 10d1078..c5bdede 100644
--- a/docs/manpages/nfdc-status.rst
+++ b/docs/manpages/nfdc-status.rst
@@ -4,7 +4,7 @@
 SYNOPSIS
 --------
 | nfdc status [show]
-| nfdc status report [<format>]
+| nfdc status report [<FORMAT>]
 
 DESCRIPTION
 -----------
@@ -22,7 +22,7 @@
 
 OPTIONS
 -------
-<format>
+<FORMAT>
     The format of NFD status report, either ``text`` or ``xml``.
     The default is ``text``.