test: log: Rename log main test file to log_ut.c

The current name is the same as the main test runner file. Rename it to
avoid confusion.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Reviewed-by: NHeinrich Schuchardt <xypron.glpk@gmx.de>

test/log/Makefile

@@ -7,7 +7,7 @@ obj-$(CONFIG_CMD_LOG) += log_filter.o
 
 ifdef CONFIG_UT_LOG
 
-obj-y += test-main.o
+obj-y += log_ut.o
 
 ifdef CONFIG_SANDBOX
 obj-$(CONFIG_LOG_SYSLOG) += syslog_test.o