Simplify cmake. Mention xz in no-lzma warning.
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 64e6676..9c7a017 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -34,33 +34,24 @@
 include(CheckStructHasMember)
 include(TestBigEndian)
 include(GNUInstallDirs)
+
 if(ENABLE_COMMONCRYPTO)
   check_include_files(CommonCrypto/CommonCrypto.h COMMONCRYPTO_FOUND)
-else()
-  set(COMMONCRYPTO_FOUND FALSE)
 endif()
 if(ENABLE_GNUTLS)
   find_package(Nettle 3.0)
   find_package(GnuTLS)
-else()
-  set(GNUTLS_FOUND FALSE)
 endif()
 if(ENABLE_MBEDTLS)
   find_package(MbedTLS 1.0)
-else()
-  set(MBEDTLS_LIBRARIES FALSE)
 endif()
 if(ENABLE_OPENSSL)
   find_package(OpenSSL)
-else()
-  set(OPENSSL_FOUND FALSE)
 endif()
 if(WIN32)
   if(ENABLE_WINDOWS_CRYPTO)
     set(WINDOWS_CRYPTO_FOUND TRUE)
   endif()
-else()
-  set(WINDOWS_CRYPTO_FOUND FALSE)
 endif()
 
 option(BUILD_SHARED_LIBS "Build shared libraries" ON)
@@ -200,7 +191,7 @@
   if(LIBLZMA_FOUND)
     set(HAVE_LIBLZMA 1)
   else()
-    message(WARNING "-- lzma library not found; lzma support disabled")
+    message(WARNING "-- lzma library not found; lzma/xz support disabled")
   endif(LIBLZMA_FOUND)
 endif(ENABLE_LZMA)