usb: gadget: f_sourcesink.c: correct a copy-paste misnomer
usb: gadget: f_sourcesink.c: correct a copy-paste misnomer

acm was the first function to be converted and it seems that its
code served as a base for converting f_sourcesink to the new function
interface. source_sink has nothing to do with acm, though.

Signed-off-by: Andrzej Pietrasiewicz <0bcd4dade8bc9135441847460b651a5ef589ec79@samsung.com>
Signed-off-by: Kyungmin Park <504c23c4986a3760712724894be3105092c27331@samsung.com>
Signed-off-by: Felipe Balbi <94dddeeef08b001e003cce128ddc162a4e2c6cd2@ti.com>

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