Documentation/fb/vesafb.txt: "inverse" option corrections

Spell the vesafb "inverse" option correctly and tell what it does.
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-fbdev@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: Antonino A. Daplas <adaplas@gmail.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Documentation/fb/vesafb.txt

@@ -114,11 +114,11 @@ to turn it on.
 
 You can pass options to vesafb using "video=vesafb:option" on
 the kernel command line.  Multiple options should be separated
-by comma, like this: "video=vesafb:ypan,invers"
+by comma, like this: "video=vesafb:ypan,inverse"
 
 Accepted options:
 
-invers	no comment...
+inverse	use inverse color map
 
 ypan	enable display panning using the VESA protected mode 
 	interface.  The visible screen is just a window of the