sh: remove -Werror from Makefiles

The sh build is full of warnings when building with gcc 9.2.1.  While
fixing those would be great, at least avoid failing the build.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rich Felker <dalias@libc.org>

arch/sh/kernel/Makefile

@@ -47,5 +47,3 @@ obj-$(CONFIG_DWARF_UNWINDER)	+= dwarf.o
 obj-$(CONFIG_PERF_EVENTS)	+= perf_event.o perf_callchain.o
 obj-$(CONFIG_DMA_NONCOHERENT)	+= dma-coherent.o
 obj-$(CONFIG_HAVE_HW_BREAKPOINT)		+= hw_breakpoint.o
-
-ccflags-y := -Werror

arch/sh/lib/Makefile

@@ -30,5 +30,3 @@ memset-$(CONFIG_CPU_SH4)	:= memset-sh4.o
 lib-$(CONFIG_MMU)		+= copy_page.o __clear_user.o
 lib-$(CONFIG_MCOUNT)		+= mcount.o
 lib-y				+= $(memcpy-y) $(memset-y) $(udivsi3-y)
-
-ccflags-y := -Werror

arch/sh/mm/Makefile

@@ -43,5 +43,3 @@ obj-$(CONFIG_UNCACHED_MAPPING)	+= uncached.o
 obj-$(CONFIG_HAVE_SRAM_POOL)	+= sram.o
 
 GCOV_PROFILE_pmb.o := n
-
-ccflags-y := -Werror