Remove remains of failed merge attempt (initramfs=true)

The line previous to initramfs=true is missing a backslash character
("\") at the end. As a result, initramfs=true is not part of
LINUX_MAKE_FLAGS. This appears to be the result of a failed merge
attempt from over four years ago.

The Linux kernel apparently builds just fine even without initramfs=true,
so let's just remove it.

Change-Id: I23016b107f45fc589975fec03bdecca9268eda85
diff --git a/linux/linux.mk b/linux/linux.mk
index 1320e9a..88b83f2 100644
--- a/linux/linux.mk
+++ b/linux/linux.mk
@@ -45,10 +45,6 @@
 	INSTALL_MOD_PATH=$(TARGET_DIR) \
 	CROSS_COMPILE="$(CCACHE) $(TARGET_CROSS)" \
 	DEPMOD=$(HOST_DIR)/usr/sbin/depmod
-	initramfs=true
-# (initramfs=true replaces the $(initramfs) build command with 'true',
-# effectively making the kernel build scripts never replace the initramfs
-# with a different one; making the initramfs is our job in buildroot.)
 
 # Get the real Linux version, which tells us where kernel modules are
 # going to be installed in the target filesystem.