of: fix uninitialized variable warning for overlay test

gcc warns that an empty device tree would cause undefined behavior:

drivers/of/unittest.c: In function 'of_unittest':
drivers/of/unittest.c:2199:25: warning: 'last_sibling' may be used uninitialized in this function [-Wmaybe-uninitialized]

This adds an initialization of the variable to zero, which we handle
correctly.

Fixes: 81d0848fc8d2 ("of: Add unit tests for applying overlays")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rob Herring <robh@kernel.org>

diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index 12597ff8cfb0b05e619add7c4e731ce890302f8b..6b8f3e6aa43c2c144d207b49bc69a0e25e223139 100644 (file)
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -2192,7 +2192,7 @@ static __init void of_unittest_overlay_high_level(void)
 
        mutex_lock(&of_mutex);
 
-       for (np = of_root->child; np; np = np->sibling)
+       for (last_sibling = np = of_root->child; np; np = np->sibling)
                last_sibling = np;
 
        if (last_sibling)