samples: seccomp: turn CONFIG_SAMPLE_SECCOMP into a bool option

The prompt of CONFIG_SAMPLE_SECCOMP claims this is "loadable module
only", which is invalid.

samples/seccomp/ only contains host programs, so having it tristate
is pointless.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

samples/Kconfig

@@ -103,8 +103,8 @@ config SAMPLE_CONNECTOR
 	  See also Documentation/connector/connector.txt
 
 config SAMPLE_SECCOMP
-	tristate "Build seccomp sample code -- loadable modules only"
-	depends on SECCOMP_FILTER && m
+	bool "Build seccomp sample code"
+	depends on SECCOMP_FILTER
 	help
 	  Build samples of seccomp filters using various methods of
 	  BPF filter construction.

samples/seccomp/Makefile

@@ -40,5 +40,5 @@ HOSTLDLIBS_bpf-fancy += $(MFLAG)
 HOSTLDLIBS_dropper += $(MFLAG)
 HOSTLDLIBS_user-trap += $(MFLAG)
 endif
-always := $(hostprogs-m)
+always := $(hostprogs-y)
 endif