[PARISC] parisc: "extern inline" -> "static inline"

"extern inline" will have different semantics with gcc 4.3, and "static
inline" is correct here.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Matthew Wilcox <willy@debian.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>