iris: Fixup copy'n'paste mistake in Makefile.sources

In changing iris_seqno.[ch] to iris_fine_fence.[ch] and moving the
lines earlier, the newline escape was forgotten.

Fixes: 034329128b ("iris: Rename iris_seqno to iris_fine_fence")
Reviewed-by: Eric Engestrom <eric@engestrom.ch>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5264>

src/gallium/drivers/iris/Makefile.sources

@@ -42,7 +42,7 @@ IRIS_C_SOURCES = \
 	iris_fence.c \
 	iris_fence.h \
 	iris_fine_fence.c \
-	iris_fine_fence.h
+	iris_fine_fence.h \
 	iris_formats.c \
 	iris_genx_macros.h \
 	iris_genx_protos.h \
@@ -57,4 +57,4 @@ IRIS_C_SOURCES = \
 	iris_resource.c \
 	iris_resource.h \
 	iris_screen.c \
-	iris_screen.h \
+	iris_screen.h