build: remove unnecessary sets (NFC)

The default values are not referenced after the cached value is set above.  The
set only complicates the SDK configuration and accomplishes nothing.  Remove the
dead code.  NFC.

Author: compnerd

CMakeLists.txt

@@ -739,12 +739,6 @@ if(swift_build_android AND NOT "${SWIFT_ANDROID_NDK_PATH}" STREQUAL "")
     message(FATAL_ERROR "A Darwin or Linux host is required to build the Swift runtime for Android")
   endif()
 
-  if(("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin" AND NOT swift_build_osx) OR
-     ("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux" AND NOT swift_build_linux))
-    set(SWIFT_PRIMARY_VARIANT_SDK_default "ANDROID")
-    set(SWIFT_PRIMARY_VARIANT_ARCH_default "armv7")
-  endif()
-
   if("${SWIFT_SDK_ANDROID_ARCHITECTURES}" STREQUAL "")
     set(SWIFT_SDK_ANDROID_ARCHITECTURES armv7;aarch64)
   endif()