Documentation/CodingStyle: allow multiple return statements per function

A surprising number of newbies interpret this section to mean that only
one return statement is allowed per function. Part of the problem is that
the "one return statement per function" rule is an actual style guideline
that people are used to from other projects.

Signed-off-by: Dan Carpenter <[e-mail]>
Cc: Eduardo Valentin <[e-mail]>
Cc: Rob Landley <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

Documentation/CodingStyle

···
 used frequently by compilers in form of the unconditional jump instruction.
 
 The goto statement comes in handy when a function exits from multiple
-locations and some common work such as cleanup has to be done.
+locations and some common work such as cleanup has to be done.  If there is no
+cleanup needed then just return directly.
 
 The rationale is: