board_init: remove meaningless increment in board_init_f_init_reserve()

The base is not used in the code that follows this increment.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
diff --git a/common/init/board_init.c b/common/init/board_init.c
index 3bc7994..f7c8a17 100644
--- a/common/init/board_init.c
+++ b/common/init/board_init.c
@@ -157,8 +157,6 @@
 #if CONFIG_VAL(SYS_MALLOC_F_LEN)
 	/* go down one 'early malloc arena' */
 	gd->malloc_base = base;
-	/* next alloc will be higher by one 'early malloc arena' size */
-	base += CONFIG_VAL(SYS_MALLOC_F_LEN);
 #endif
 
 	if (CONFIG_IS_ENABLED(SYS_REPORT_STACK_F_USAGE))