mtd: tests: incorporate error message for mtdtest_read()

All callers of mtdtest_read() print the same error message on failure.
This incorporates the error message to mtdtest_read() and removes them
from the callers.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/tests/readtest.c

@@ -55,8 +55,6 @@ static int read_eraseblock_by_page(int ebnum)
 		memset(buf, 0 , pgsize);
 		ret = mtdtest_read(mtd, addr, pgsize, buf);
 		if (ret) {
-			pr_err("error: read failed at %#llx\n",
-			       (long long)addr);
 			if (!err)
 				err = ret;
 		}