SSL: fixed SSL shutdown on lingering close.

Ensure c->recv is properly reset to ngx_recv if SSL_shutdown()
blocks on writing.

The bug had appeared in 554c6ae25ffc.

src/event/ngx_event_openssl.c

diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
index fd2b92f..93a6ae4 100644
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -2880,6 +2880,7 @@
 
         SSL_free(c->ssl->connection);
         c->ssl = NULL;
+        c->recv = ngx_recv;
 
         return NGX_OK;
     }
@@ -2925,6 +2926,7 @@
         if (n == 1) {
             SSL_free(c->ssl->connection);
             c->ssl = NULL;
+            c->recv = ngx_recv;
 
             return NGX_OK;
         }
@@ -2967,6 +2969,7 @@
         if (sslerr == SSL_ERROR_ZERO_RETURN || ERR_peek_error() == 0) {
             SSL_free(c->ssl->connection);
             c->ssl = NULL;
+            c->recv = ngx_recv;
 
             return NGX_OK;
         }
@@ -2977,6 +2980,7 @@
 
         SSL_free(c->ssl->connection);
         c->ssl = NULL;
+        c->recv = ngx_recv;
 
         return NGX_ERROR;
     }

src/http/ngx_http_request.c

diff --git a/src/http/ngx_http_request.c b/src/http/ngx_http_request.c
index 12a68a9..e954c7c 100644
--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -3397,8 +3397,6 @@
             c->ssl->handler = ngx_http_set_lingering_close;
             return;
         }
-
-        c->recv = ngx_recv;
     }
 #endif
 

src/http/v2/ngx_http_v2.c

diff --git a/src/http/v2/ngx_http_v2.c b/src/http/v2/ngx_http_v2.c
index 58916a1..77b60d4 100644
--- a/src/http/v2/ngx_http_v2.c
+++ b/src/http/v2/ngx_http_v2.c
@@ -739,8 +739,6 @@
             c->ssl->handler = ngx_http_v2_lingering_close;
             return;
         }
-
-        c->recv = ngx_recv;
     }
 #endif