compat-wireless: fix pr_fmt compile warnings

compat-wireless: fix pr_fmt compile warnings

This took a while to figure out... Thought this was impossible
to fix, but the fix is quite simple: fix this upstream. The
assumption by drivers when upstream is that you should #define
pr_fmt *prior* to including <linux/printk.h> but -- the assumption
is incorrect given that if a subsystem includes printk.h for
anything that the subsystem needs then the module would be defining
the pr_fmt. The proper usage then for pr_fmt then is to always
undef it first, and also include <linux/printk.h>.

When test cross compiling against 2.6.24 - 3.3 I notice that including
<linux/kernel.h> also helps, so do this for now. There may be
another reason why that is required but we can figure that out later.

This patch should be broken down into chunks and submitted upstream.
This shaves off compilation time down from 1 hour to 1/2 hour!

mcgrof@flash ~/devel/compat-wireless (git::master)$ time ckmake
Trying kernel                     3.2.2-030202-generic  [OK]
Trying kernel                    3.1.10-030110-generic  [OK]
Trying kernel                    3.0.18-030018-generic  [OK]
Trying kernel                  2.6.39-02063904-generic  [OK]
Trying kernel                  2.6.38-02063808-generic  [OK]
Trying kernel                  2.6.37-02063706-generic  [OK]
Trying kernel                  2.6.36-02063604-generic  [OK]
Trying kernel                  2.6.35-02063512-generic  [OK]
Trying kernel                  2.6.34-02063410-generic  [OK]
Trying kernel                  2.6.33-02063305-generic  [OK]
Trying kernel                  2.6.32-02063255-generic  [OK]
Trying kernel                  2.6.31-02063113-generic  [OK]
Trying kernel                  2.6.30-02063010-generic  [OK]
Trying kernel                  2.6.29-02062906-generic  [OK]
Trying kernel                  2.6.28-02062810-generic  [OK]
Trying kernel                    2.6.27-020627-generic  [OK]
Trying kernel                    2.6.26-020626-generic  [OK]
Trying kernel                    2.6.25-020625-generic  [OK]
Trying kernel                    2.6.24-020624-generic  [OK]

real    29m17.269s
user    75m56.693s
sys     10m48.469s

Signed-off-by: Luis R. Rodriguez <mcgrof@frijolero.org>