NetworkPkg/Library: Fix various typos

Fix various typos in comments and documentation.

Cc: Jiaxin Wu <jiaxin.wu@intel.com>
Cc: Siyuan Fu <siyuan.fu@intel.com>
Cc: Maciej Rabeda <maciej.rabeda@intel.com>
Signed-off-by: Antoine Coeur <coeur@gmx.fr>
Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>
Reviewed-by: Maciej Rabeda <maciej.rabeda@intel.com>
Signed-off-by: Philippe Mathieu-Daude <philmd@redhat.com>
Message-Id: <20200207010831.9046-43-philmd@redhat.com>

NetworkPkg/Library/DxeNetLib/NetBuffer.c

@@ -602,7 +602,7 @@ NetbufGetFragment (
 
   if (HeadSpace != 0) {
     //
-    // Allocate an extra block to accomdate the head space.
+    // Allocate an extra block to accommodate the head space.
     //
     BlockOpNum++;
 
@@ -791,7 +791,7 @@ NetbufFromExt (
 
         if (Len == 0) {
           //
-          // Increament the index number to point to the next
+          // Increment the index number to point to the next
           // non-empty fragment.
           //
           Index++;