cmake: Fix static .lib overwriting on Windows.

src/CMakeLists.txt

@@ -190,6 +190,11 @@ install(
 if (WITH_STATIC_LIB)
   add_library(${LIBSSH_STATIC_LIBRARY} STATIC ${libssh_SRCS})
 
+  if (MSVC)
+    set(OUTPUT_SUFFIX static)
+  else (MSVC)
+    set(OUTPUT_SUFFIX )
+  endif (MSVC)
   set_target_properties(
     ${LIBSSH_STATIC_LIBRARY}
       PROPERTIES
@@ -199,6 +204,8 @@ if (WITH_STATIC_LIB)
           ${LIBRARY_SOVERSION}
         OUTPUT_NAME
           ssh
+        ARCHIVE_OUTPUT_DIRECTORY
+          ${CMAKE_CURRENT_BINARY_DIR}/${OUTPUT_SUFFIX}
   )
 
   if (WIN32)
@@ -214,7 +221,7 @@ if (WITH_STATIC_LIB)
     TARGETS
       ${LIBSSH_STATIC_LIBRARY}
     DESTINATION
-      ${LIB_INSTALL_DIR}
+      ${LIB_INSTALL_DIR}/${OUTPUT_SUFFIX}
     COMPONENT
       libraries
   )