patch 8.2.0156: various typos in source files and tests

Problem:    Various typos in source files and tests.
Solution:   Fix the typos. (Emir Sari, closes #5532)
diff --git a/src/buffer.c b/src/buffer.c
index f56ff0b..7ff8097 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -1690,7 +1690,7 @@
     set_bufref(&prevbufref, prevbuf);
     set_bufref(&newbufref, buf);
 
-    // Autocommands may delete the curren buffer and/or the buffer we wan to go
+    // Autocommands may delete the current buffer and/or the buffer we want to go
     // to.  In those cases don't close the buffer.
     if (!apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf)
 	    || (bufref_valid(&prevbufref)
@@ -1713,6 +1713,7 @@
 #endif
 	{
 	    win_T  *previouswin = curwin;
+
 	    if (prevbuf == curbuf)
 		u_sync(FALSE);
 	    close_buffer(prevbuf == curwin->w_buffer ? curwin : NULL, prevbuf,