net/macb: memory barriers cleanup
net/macb: memory barriers cleanup

Remove a couple of unneeded barriers and document the remaining ones.

Signed-off-by: Havard Skinnemoen <311143ce1ada4d216412d2f25a9f5931ecb1d51f@skinnemoen.net>
[45b517be0e5ec6dc3a39715767c1d18e090d39b4@atmel.com: split patch in topics]
Signed-off-by: Nicolas Ferre <45b517be0e5ec6dc3a39715767c1d18e090d39b4@atmel.com>
Tested-by: Joachim Eastwood <6f54d78a4cd927eb19dd17c34117bfc80f7abcf7@gmail.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs