Documentation: remove the linker command line switch --static from the final…

Documentation: remove the linker command line switch --static from the final step described in the cross-compilation guide

Static linking of the binary criu isn't supported any more.
Reported-by: riya khanna <riyakhanna1983@gmail.com>
Signed-off-by: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Documentation/HOWTO.cross-compile

@@ -28,4 +28,4 @@ This HOWTO explains how to cross-compile CRIU on x86
 12. Compile and install protobuf-c.
 13. Compile CRIU:
 
-     ARCH=<target arch> CROSS_COMPILE=$TARGET- CFLAGS=`pkg-config --cflags libprotobuf-c` LDFLAGS="`pkg-config --libs libprotobuf-c` --static" make
+     ARCH=<target arch> CROSS_COMPILE=$TARGET- CFLAGS=`pkg-config --cflags libprotobuf-c` LDFLAGS="`pkg-config --libs libprotobuf-c`" make