can: mcp251x: read-modify-write eflag only when needed
can: mcp251x: read-modify-write eflag only when needed

Use read-modify-write instead of a simple write to change the register
contents, to close existing the race window between the original manual
read and write.

Signed-off-by: Sascha Hauer <c00cbc2b736c26791a3822db86f8796fe9efff67@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <4a0ea1158d3cc63151119c05b1bff00c0bdbf421@pengutronix.de>
Acked-by: Wolfgang Grandegger <5aa1976eca1fee4e35c7b71ec8e8a0ebad9da3d1@grandegger.com>

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