asm-generic/user.h: Fix spelling in comment

Fix two misspellings.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

asm-generic: add generic versions of common headers

These are all kernel internal interfaces that get copied
around a lot. In most cases, architectures can provide
their own optimized versions, but these generic versions
can work as well.

I have tried to use the most common contents of each
header to allow existing architectures to migrate easily.

Thanks to Remis for suggesting a number of cleanups.

Signed-off-by: Remis Lima Baima <remis.developer@googlemail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>