Revert "glShaderSource should respect length parameter"

Reason: breaks dEQP-GLES2.functional.shader_api in negative length parameter case
This reverts commit 481836a5a6ed03e14f9df9745c3734ffc5d1a204.
Change-Id: I8989aaebc7feffe1462f741ceda8f56303b19279
diff --git a/system/GLESv2_enc/GL2Encoder.cpp b/system/GLESv2_enc/GL2Encoder.cpp
index 686323b..783812c 100755
--- a/system/GLESv2_enc/GL2Encoder.cpp
+++ b/system/GLESv2_enc/GL2Encoder.cpp
@@ -1743,15 +1743,8 @@
 
     // Track original sources---they may be translated in the backend
     std::vector<std::string> orig_sources;
-    if (length) {
-        for (int i = 0; i < count; i++) {
-            orig_sources.push_back(std::string((const char*)(string[i]),
-                                               (const char*)(string[i]) + length[i]));
-        }
-    } else {
-        for (int i = 0; i < count; i++) {
-            orig_sources.push_back(std::string((const char*)(string[i])));
-        }
+    for (int i = 0; i < count; i++) {
+        orig_sources.push_back(std::string((const char*)(string[i])));
     }
     shaderData->sources = orig_sources;