package/linux-pam: remove flex dependency

linux-pam 1.2.0 removed the use of yywrap, so the flex dependency is not
needed now (host-flex is still needed).

Fixes: #47
Signed-off-by: Damien Thébault <damien.thebault@gmail.com>
Signed-off-by: Arnout Vandecappelle <arnout@mind.be>
(cherry picked from commit 600e273487)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/linux-pam/Config.in

@@ -5,7 +5,6 @@ config BR2_PACKAGE_LINUX_PAM
 	depends on !BR2_STATIC_LIBS
 	depends on BR2_USE_MMU # fork()
 	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_9 # C11/stdatomic.h
-	select BR2_PACKAGE_FLEX
 	help
 	  A Security Framework that Provides Authentication for
 	  Applications

package/linux-pam/linux-pam.mk

@@ -16,7 +16,7 @@ LINUX_PAM_CONF_OPTS = \
 	--disable-regenerate-docu \
 	--enable-securedir=/lib/security \
 	--libdir=/lib
-LINUX_PAM_DEPENDENCIES = flex host-flex host-pkgconf \
+LINUX_PAM_DEPENDENCIES = host-flex host-pkgconf \
 	$(if $(BR2_PACKAGE_LIBXCRYPT),libxcrypt) \
 	$(TARGET_NLS_DEPENDENCIES)
 LINUX_PAM_LICENSE = BSD-3-Clause