Be explicit about how we're placing part of the on-disk name into
the extension. Appease coverity. NFC.
Index: denode.h
===================================================================
RCS file: /cvsroot/src/sys/fs/msdosfs/denode.h,v
retrieving revision 1.24
diff -u -p -u -r1.24 denode.h
--- denode.h	8 Jul 2014 09:21:52 -0000	1.24
+++ denode.h	14 Jan 2017 17:06:10 -0000
@@ -212,7 +212,8 @@ struct denode {
 #define DE_INTERNALIZE32(dep, dp)			\
 	 ((dep)->de_StartCluster |= getushort((dp)->deHighClust) << 16)
 #define DE_INTERNALIZE(dep, dp)				\
-	(memcpy((dep)->de_Name, (dp)->deName, 11),	\
+	(memcpy((dep)->de_Name, (dp)->deName, 8),	\
+	 memcpy((dep)->de_Name+8, (dp)->deExtension, 3),\
 	 (dep)->de_Attributes = (dp)->deAttributes,	\
 	 (dep)->de_CHun = (dp)->deCHundredth,		\
 	 (dep)->de_CTime = getushort((dp)->deCTime),	\
@@ -229,7 +230,8 @@ struct denode {
 #define DE_EXTERNALIZE16(dp, dep)			\
 	 putushort((dp)->deHighClust, 0)
 #define DE_EXTERNALIZE(dp, dep)				\
-	(memcpy((dp)->deName, (dep)->de_Name, 11),	\
+	(memcpy((dp)->deName, (dep)->de_Name, 8),	\
+	 memcpy((dp)->deExtension, (dep)->de_Name+8, 3),\
 	 (dp)->deAttributes = (dep)->de_Attributes,	\
 	 (dp)->deCHundredth = (dep)->de_CHun,		\
 	 putushort((dp)->deCTime, (dep)->de_CTime),	\