USB: Standardize inclusion protection and add where missing.

For the header files in include/linux/usb, add missing multiple
inclusion protection and standardize what's already there.  The
apparent standards:

  * macro name of __LINUX_USB_headerfile_H
  * inclusion protection placed after leading comment block
  * macro name added as a comment on the final #endif
  * any obvious trivial whitespace cleanup associated with the above

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h
index 21b4a1c..f1b7434 100644
--- a/include/linux/usb/serial.h
+++ b/include/linux/usb/serial.h
@@ -10,7 +10,6 @@
  *
  */
 
-
 #ifndef __LINUX_USB_SERIAL_H
 #define __LINUX_USB_SERIAL_H
 
@@ -340,5 +339,5 @@
 
 
 
-#endif	/* ifdef __LINUX_USB_SERIAL_H */
+#endif /* __LINUX_USB_SERIAL_H */