Fix misspelling of 'suppress' in docs

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-checkout.txt

@@ -35,7 +35,7 @@ working tree.
 OPTIONS
 -------
 -q::
-	Quiet, supress feedback messages.
+	Quiet, suppress feedback messages.
 
 -f::
 	Proceed even if the index or the working tree differs

Documentation/git-send-email.txt

@@ -88,7 +88,7 @@ The --cc option must be repeated for each user you want on the cc list.
         If this is set, do not add the From: address to the cc: list, if it
         shows up in a From: line.
         Default is the value of 'sendemail.suppressfrom' configuration value;
-        if that is unspecified, default to --no-supress-from.
+        if that is unspecified, default to --no-suppress-from.
 
 --thread, --no-thread::
 	If this is set, the In-Reply-To header will be set on each email sent.