patch 9.0.0376: clang warns for dead assignments

Problem:    Clang warns for dead assignments.
Solution:   Adjust the code. (Yegappan Lakshmanan, closes #11048)
diff --git a/src/viminfo.c b/src/viminfo.c
index acdf618..546103e 100644
--- a/src/viminfo.c
+++ b/src/viminfo.c
@@ -2324,7 +2324,7 @@
 		    // Read the next line.  If it has the "*" mark compare the
 		    // time stamps.  Write entries from "buflist" that are
 		    // newer.
-		    if (!(eof = viminfo_readline(virp)) && line[0] == TAB)
+		    if (!viminfo_readline(virp) && line[0] == TAB)
 		    {
 			did_read_line = TRUE;
 			if (line[1] == '*')