brcm80211: Convert printk(KERN_DEBUG to pr_debug

Use pr_debug to allow dynamic debugging to work.

Move an #endif to allow brcmf_dbg_hex_dump
to be outside the #if/#endif block.
Move a const char* declaration to be inside a
pr_debug so the function doesn't need a #if/#endif
block.
Don't use temporaries in debugging functions so
the code can be optimized away.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>