bus: bt1-axi: Use sysfs_streq instead of strncmp

There is a ready-to-use method to compare a retrieved from a sysfs node
string with another string. It treats both NUL and newline-then-NUL as
equivalent string terminations. So use it instead of manually truncating
the line length in the strncmp() method.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Serge Semin <[e-mail]>
Cc: Alexey Malahov <[e-mail]>
Cc: Olof Johansson <[e-mail]>
Cc: Andy Shevchenko <[e-mail]>
Cc: [e-mail]
Signed-off-by: Arnd Bergmann <[e-mail]>

drivers/bus/bt1-axi.c

···
 	 * error while unaligned writing - the AXI bus write error handled
 	 * by this driver.
 	 */
-	if (!strncmp(data, "bus", 3))
+	if (sysfs_streq(data, "bus"))
 		readb(axi->qos_regs);
-	else if (!strncmp(data, "unaligned", 9))
+	else if (sysfs_streq(data, "unaligned"))
 		writeb(0, axi->qos_regs);
 	else
 		return -EINVAL;